#!/home/mui/proj/perl-devel/bin/perl
##
# Perldaemon process to check a mount point. Send errors to logfile.
##

use strict;
use POSIX qw(setsid);

##
# Signals to Trap and Handle
##
$SIG{'INT' } = 'interrupt';
$SIG{'HUP' } = 'interrupt';
$SIG{'ABRT'} = 'interrupt';
$SIG{'QUIT'} = 'interrupt';
$SIG{'TRAP'} = 'interrupt';
$SIG{'STOP'} = 'interrupt';
$SIG{'TERM'} = 'interrupt';

# Globals
my $DELAY 	=  300;
my $MNT 	= "/mnt/net/ajaxx";
my $LOG 	= "/tmp/mntchkd.log";
my $PROGRAM = "mntchkd";

# Input validation bits
if ((@ARGV <= 0) || (@ARGV >= 7)) {
        print "syntax error\n";
        usage();
        exit 1;
}

# Check for usage message first
if ($ARGV[0] eq "usage") {
        usage();
        exit 0;
}

# XXX Still need to add these funcs
for (my $i = 0; $i <@ARGV; $i++) {
	if ($ARGV[$i] =~ /^-version|-V$/) {
        my $do_version = 1;
    } elsif ($ARGV[$i] eq '-usage') {
        my $do_usage = 1;
	} elsif ($ARGV[$i] eq '-m') {
		$MNT = $ARGV[++$i];
	} elsif ($ARGV[$i] eq '-l') {
		$LOG = $ARGV[++$i];
	} elsif ($ARGV[$i] eq '-d') {
		$DELAY = $ARGV[++$i];
    } else {
        usage();
    }
}

unless(my $pid = fork()) {
	exit if $pid;
	setsid;
	umask 0;
	my $date = longfmt();
	appendfile($LOG, "$date Starting $PROGRAM");
	while(1) {
		$date = longfmt();
		if ( -d "$MNT" ) {
			appendfile($LOG, "$date Mount point $MNT present");
		} else {
			appendfile($LOG, "$date Mount point $MNT missing");
		}
	sleep $DELAY;
	}
}

##
# Append file: Append a string to a file.
##
sub appendfile {
	my ($fp, $msg) = @_;

	if (open(FILE, ">>$fp")) {
		print FILE ("$msg\n");
		close FILE;
	}
}

##
# Insert 0: Fix up date strings
##
sub insert0 {
	my ($date) = shift;

	if ($date < 10) {
		return "0$date";
	} 

	return $date;
}

##
# Interrupt: Simple interrupt handler
##
sub interrupt {
	appendfile($LOG, "caught @_ exiting");
	print "caught @_ exiting\n";
	die;
}

##
# Long format: Custom datestring for the logfile
##
sub longfmt {
	my ($sec,$min,$hour,$mday,$mon,$year,
		$wday,$yday,$iddst) = localtime(time);
	my $datestring;

	$year += 1900;
	$mon++;
	$mon  = insert0($mon);
	$mday = insert0($mday);
	$min  = insert0($min);
	$datestring = "$year-$mon-$mday $hour:$min";

	return($datestring);
}

sub usage {
    print "$PROGRAM [option argument][option argument]...\n";
    print "$PROGRAM [-d delay][-m mountpoint][-l logfile]\n";
    print "Options:\n";
    print "    -d delay     Set check delaytime in seconds to delay\n";
    print "    -m directory Set mountpount to directory\n";
    print "    -l logfile   Send log messages to logfile\n";
}